Illuminated and non-illuminated heavy duty oil tight push-pull switch operators are well known and are frequently designed as illustrated in U.S. Pat. No. 3,472,986 which was granted to James E. Stallman on Oct. 14, 1969, to be used with other modular components to provide a large number of combinations of switching capabilities. One form of an operator, as illustrated in the Stallman patent, known as a momentary push-pull operator, included a spring-biased cam structure which normally maintained a plunger in a neutral position and permitted the plunger to be either pushed or pulled from the neutral position to selectively actuate switches that are mounted at the rear of the operator. While the structure therein disclosed provided satisfactory service, objections were made to its use because of the lack of detent action particularly if the stem thereof required only limited travel from its neutral position to effect actuation of the switch.
Operators of the type hereinafter disclosed are frequently used in machine shops and the like where minute iron particles are present. Therefore designers of industrial control switching devices usually have avoided including permanent magnets in devices because of the propensity of permanent magnets to attract the iron filings which would cause the devices embodying permanent magnets to have a whiskered appearance within a short time after being placed in service.